events {
    worker_connections 1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    # Logging
    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                    '$status $body_bytes_sent "$http_referer" '
                    '"$http_user_agent" "$http_x_forwarded_for"';

    access_log /var/log/nginx/access.log main;
    error_log /var/log/nginx/error.log warn;

    # Basic Settings
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    client_max_body_size 50M;

    # Gzip Compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1000;
    gzip_proxied any;
    gzip_comp_level 6;
    gzip_types
        text/plain
        text/css
        text/xml
        text/javascript
        application/json
        application/javascript
        application/xml+rss
        application/atom+xml
        image/svg+xml;

    # Rate Limiting
    limit_req_zone $binary_remote_addr zone=api:10m rate=10r/s;
    limit_req_zone $binary_remote_addr zone=login:10m rate=5r/m;

    # Upstream definition
    upstream app {
        server app:3000;
        keepalive 32;
    }

    # HTTP to HTTPS redirect
    server {
        listen 80;
        server_name _;

        # Let's Encrypt challenge
        location /.well-known/acme-challenge/ {
            root /var/www/certbot;
        }

        # Redirect all other traffic to HTTPS
        location / {
            return 301 https://$server_name$request_uri;
        }
    }

    # HTTPS Server
    server {
        listen 443 ssl http2;
        server_name your-domain.com www.your-domain.com;

        # SSL Configuration
        ssl_certificate /etc/nginx/ssl/cert.pem;
        ssl_certificate_key /etc/nginx/ssl/key.pem;
        ssl_protocols TLSv1.2 TLSv1.3;
        ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!3DES:!MD5:!PSK;
        ssl_prefer_server_ciphers off;
        ssl_session_cache shared:SSL:10m;
        ssl_session_timeout 10m;

        # HSTS
        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;

        # Security Headers
        add_header X-Frame-Options "SAMEORIGIN" always;
        add_header X-XSS-Protection "1; mode=block" always;
        add_header X-Content-Type-Options "nosniff" always;
        add_header Referrer-Policy "strict-origin-when-cross-origin" always;
        add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:; connect-src 'self'; frame-ancestors 'self';" always;

        # Next.js Static Assets (long cache)
        location /_next/static {
            proxy_pass http://app;
            proxy_cache_valid 200 1y;
            add_header Cache-Control "public, immutable, max-age=31536000";
            add_header X-Cache-Status $upstream_cache_status;
        }

        # Images and media (medium cache)
        location ~* \.(jpg|jpeg|png|gif|ico|svg|webp|pdf)$ {
            proxy_pass http://app;
            expires 30d;
            add_header Cache-Control "public, max-age=2592000";
        }

        # API Routes with rate limiting
        location /api/ {
            # Rate limiting
            limit_req zone=api burst=20 nodelay;

            # Special rate limiting for auth endpoints
            location /api/auth/ {
                limit_req zone=login burst=5 nodelay;
                proxy_pass http://app;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection 'upgrade';
                proxy_set_header Host $host;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header X-Forwarded-Proto $scheme;
                proxy_cache_bypass $http_upgrade;
            }

            proxy_pass http://app;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection 'upgrade';
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_cache_bypass $http_upgrade;

            # API response headers
            add_header X-Content-Type-Options nosniff;
            add_header X-Frame-Options DENY;
        }

        # Admin routes (additional security)
        location /admin {
            # Additional rate limiting for admin
            limit_req zone=login burst=10 nodelay;

            proxy_pass http://app;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection 'upgrade';
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_cache_bypass $http_upgrade;
        }

        # Main application
        location / {
            proxy_pass http://app;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection 'upgrade';
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_cache_bypass $http_upgrade;

            # Basic caching for pages
            proxy_cache_valid 200 5m;
        }

        # Security: Block access to sensitive files
        location ~ /\. {
            deny all;
            access_log off;
            log_not_found off;
        }

        location ~ \.(env|git|htaccess|htpasswd)$ {
            deny all;
            access_log off;
            log_not_found off;
        }
    }
}